1. Field of the Invention The invention relates to an apparatus for bending an elongated material such as wire, strip or section bar material.
2. Description of the Related Art
In a bending apparatus known from DE Patent No. 3,523,828, each bending finger with its carrier is mounted in a tool carriage for displacement parallel to the working plane and perpendicular to the material feed direction. During the bending operation the bending finger is only displaceable in this fixed direction. In the same manner bending mandrels acting as counterstop elements are mounted in respective tool carriages. The tool carriage is mounted on prismatic guide rails for displacement parallel to the working plane and parallel to the material feed direction. This apparatus is only capable of performing simple bending operations about limited bending angles. The bending operation results in sliding displacements of the material to be bent and the only linearly displaceable bending finger relative to one another, giving rise to excessive friction forces. Since in the course of the bending operation the bending finger does no longer act on the material perpendicular to its longitudinal direction, but rather at an increasingly acute angle, deviations from the predetermined bending radius cannot be excluded as the bending operation proceeds.
Known from DE-OS 30 28 834 is an apparatus for punching and bending workpieces, in which a bending station includes two tool carriages for the linear displacement of respective bending fingers back and forth in a direction perpendicular to the material feed direction. Although the end points of the bending finger displacement can be adjusted during the bending operation within certain tolerance limits, an adjustment of the tool carriages, which are guided in a circular groove extending parallel to the work plane, is only possible after the apparatus has been stopped. The bending operation itself is hampered by the same shortcomings as in the apparatus referred to in the first place.